THE NUCLEAR CARD: The Aluminum Tube Story -- A special report.; How White House Embraced Suspect Iraq Arms Intelligence

This article was reported by David Barstow, William J. Broad and Jeff Gerth, and was written by Mr. Barstow.

Published: October 3, 2004

In 2002, at a crucial juncture on the path to war, senior members of the Bush administration gave a series of speeches and interviews in which they asserted that Saddam Hussein was rebuilding his nuclear weapons program. Speaking to a group of Wyoming Republicans in September, Vice President Dick Cheney said the United States now had ''irrefutable evidence'' -- thousands of tubes made of high-strength aluminum, tubes that the Bush administration said were destined for clandestine Iraqi uranium centrifuges, before some were seized at the behest of the United States.

Those tubes became a critical exhibit in the administration's brief against Iraq. As the only physical evidence the United States could brandish of Mr. Hussein's revived nuclear ambitions, they gave credibility to the apocalyptic imagery invoked by President Bush and his advisers. The tubes were ''only really suited for nuclear weapons programs,'' Condoleezza Rice, the president's national security adviser, explained on CNN on Sept. 8, 2002. ''We don't want the smoking gun to be a mushroom cloud.''

But almost a year before, Ms. Rice's staff had been told that the government's foremost nuclear experts seriously doubted that the tubes were for nuclear weapons, according to four officials at the Central Intelligence Agency and two senior administration officials, all of whom spoke on condition of anonymity. The experts, at the Energy Department, believed the tubes were likely intended for small artillery rockets.

The White House, though, embraced the disputed theory that the tubes were for nuclear centrifuges, an idea first championed in April 2001 by a junior analyst at the C.I.A. Senior nuclear scientists considered that notion implausible, yet in the months after 9/11, as the administration built a case for confronting Iraq, the centrifuge theory gained currency as it rose to the top of the government.

Senior administration officials repeatedly failed to fully disclose the contrary views of America's leading nuclear scientists, an examination by The New York Times has found. They sometimes overstated even the most dire intelligence assessments of the tubes, yet minimized or rejected the strong doubts of nuclear experts. They worried privately that the nuclear case was weak, but expressed sober certitude in public.

One result was a largely one-sided presentation to the public that did not convey the depth of evidence and argument against the administration's most tangible proof of a revived nuclear weapons program in Iraq.

Today, 18 months after the invasion of Iraq, investigators there have found no evidence of hidden centrifuges or a revived nuclear weapons program. The absence of unconventional weapons in Iraq is now widely seen as evidence of a profound intelligence failure, of an intelligence community blinded by ''group think,'' false assumptions and unreliable human sources.

Yet the tale of the tubes, pieced together through records and interviews with senior intelligence officers, nuclear experts, administration officials and Congressional investigators, reveals a different failure.

Far from ''group think,'' American nuclear and intelligence experts argued bitterly over the tubes. A ''holy war'' is how one Congressional investigator described it. But if the opinions of the nuclear experts were seemingly disregarded at every turn, an overwhelming momentum gathered behind the C.I.A. assessment. It was a momentum built on a pattern of haste, secrecy, ambiguity, bureaucratic maneuver and a persistent failure in the Bush administration and among both Republicans and Democrats in Congress to ask hard questions.

Precisely how knowledge of the intelligence dispute traveled through the upper reaches of the administration is unclear. Ms. Rice knew about the debate before her Sept. 2002 CNN appearance, but only learned of the alternative rocket theory of the tubes soon afterward, according to two senior administration officials. President Bush learned of the debate at roughly the same time, a senior administration official said.

Last week, when asked about the tubes, administration officials said they relied on repeated assurances by George J. Tenet, then the director of central intelligence, that the tubes were in fact for centrifuges. They also noted that the intelligence community, including the Energy Department, largely agreed that Mr. Hussein had revived his nuclear program.

''These judgments sometimes require members of the intelligence community to make tough assessments about competing interpretations of facts,'' said Sean McCormack, a spokesman for the president.

Mr. Tenet declined to be interviewed. But in a statement, he said he ''made it clear'' to the White House ''that the case for a possible nuclear program in Iraq was weaker than that for chemical and biological weapons.'' Regarding the tubes, Mr. Tenet said ''alternative views were shared'' with the administration after the intelligence community drafted a new National Intelligence Estimate in late September 2002.